Photo: Matt Winkelmeyer / Getty Images Entertainment / Getty Images
When Billie Joe Armstrong comes around, you better expect a surprise!
The Green Day frontman treated fans to an impromptu mini-concert on Friday (July 24), performing the band's 1994 hit "Basket Case" on top of an ice cream truck at San Diego Comic-Con.
The "When I Come Around" hitmaker played an acoustic set, per Billboard, while promoting the upcoming comedy Nimrods, which features the Grammy-winning band. Bandmates Mike Dirnt and Tré Cool ultimately joined Armstrong during the surprise performance.
The trio later climbed into the ice cream truck to hand out ice cream, cassettes and T-shirts to the fans in the crowd.
Nimrods, a coming-of-age film that follows three teenagers who embark on a cross-country road trip after mistakenly believing they've won a chance to open for Green Day, also stars Jenna Fischer and Mason Thames.
Watch the performance below.